中文摘要：

设计了一种新颖的、低开关功率的全光开关．将高非线性光子晶体光纤和双向抽运掺饵光纤放大器引入Sagnac环形镜内，破坏了环形镜的对称性，利用交叉相位调制作用使反向传输的两路信号光产生非线性相移，从而实现开关效应．理论分析表明：开关功率与放大器的增益倍数和光子晶体光纤非线性系数的积成反比，在实验中所得开关功率约40mw，消光比约为15．9dB，并且信号光透过率随脉冲控制光峰值功率呈余弦变化，实验结果与理论分析相吻合．

英文摘要：

We designed a novel and low switching-power all-optical fiber switch. The highly nonlinear photonic crystal fiber and the bidirectional pumped Er-dopod fiber amplifier are inserted into the Sagnac loop mirror simultaneously. The switching is realized based on cress-phase modulation because the symmetry of the loop is broken. The theoretical analysis shows that the switchingpower is inverse proportional to the product of the amplifier gain and the nonlinear coefficient of the photonic crystal fiber. In our experiment, 40 mW switching-power and 15.9 dB switching-extinction are obtained; furthermore, the transmission of signal light is a cosine function of the peak power of the control pulse. All the results of experiment well agree with the theory.